- Runny nose
- Decrease in appetite
- Coughing
- Sneezing
- Fever
- Wheezing
These symptoms usually appear in stages and not all at once, according to the CDC. In very young infants with RSV, the only symptoms may be irritability, decreased activity, and breathing difficulties.
Almost all children will get an RSV infection by their second birthday.
How effective is the vaccine?
The FDA gave its approval based on a clinical trial in which approximately 12,500 participants from around the world randomly got an Arexvy vaccine, while 12,500 others received a placebo shot.
Results from a single RSV season showed that the vaccine was 82.6 percent effective in preventing RSV-induced lower respiratory tract infections, and just over 94 percent effective in reducing the risk of a severe infection.
Participants will remain in the study through three RSV seasons to assess the duration of effectiveness, as well as the safety and effectiveness of repeat vaccination, the FDA said.
Are there any side effects?
The most commonly reported side effects by individuals who received Arexvy were injection site pain, fatigue, muscle pain, headache and joint stiffness or pain, the FDA said.
Among all clinical trial participants, atrial fibrillation within 30 days of vaccination was reported in 10 participants who received Arexvy and four participants who received the placebo.
Two other clinical trials involving Arexvy showed some concerning side effects that have warranted further review.
In one of the trials, participants received Arexvy along with an FDA-approved influenza vaccine. One person died after developing acute disseminated encephalomyelitis (ADEM), a rare type of inflammation that affects the brain and spinal cord, while a second fell ill with ADEM.
In the other study, one participant developed Guillain-Barré syndrome — a rare disorder in which the body’s immune system